If the prospect of government MPs tabling an amendment to the Queen's Speech wasn't unusual enough (it hasn't happened since 1946), it now appears that David Cameron may be prepared to take the extraordinary step of supporting them. The Sun reports that Cameron is ready to vote in favour of the Conservative amendment, which "Respectfully regrets that an EU referendum bill was not included in the gracious speech". A No. 10 source tells the paper: "The PM is determined to make as many people as possible aware how keen he is to hold this referendum.

"This amendment backs up his policy, which is a Conservative Party policy, so why shouldn’t he vote for it too?"

In other words, the Prime Minister may be about to rebel against his own government. That really would put us in uncharted territory. As the Parliament website states, by convention, "If the Queen’s Speech is amended, the Prime Minister must resign." The last time an amendment was successful was in 1924 when Labour tabled a motion of no confidence in Stanley Baldwin's Conservative government. After the motion was passed by 328 votes to 251, Baldwin resigned as prime minister and Ramsay MacDonald formed the first Labour government.

With Labour and the Liberal Democrats set to vote against the amendment (they have 314 MPs to the Tories' 305), there's almost no chance of it passing (although at least two Labour MPs, John Cryer and Kelvin Hopkins, have signed the amendment and there's always the option of abstaining...). But were the Tory rebels successful, it is clear that Cameron would either have to resign or abandon centuries of parliamentary convention.

Update: It look as if there may be an escape route for Cameron. I've just spoken to the Commons Information Office which has informed me that as a result of the Fixed-term Parliaments Act, a successful amendment to the Queen's Speech is no longer regarded as a vote of no confidence in the government. This is because, for the first time, the bill offered a legal definition of a no confidence vote - a motion stating that "That this House has no confidence in Her Majesty’s Government." - meaning that defeats on matters such as the Queen's Speech or the Budget are no longer regarded as votes of no confidence in the government. Prior to the act, as the Information Office put it, "it was a motion of no confidence if everyone agreed that it was a motion of no confidence."

A 2010 briefing note from the House of Commons Library had suggested that some ambiguity remained. It stated that it was "not clear whether a defeat on a motion or issue of confidence would count as a vote of no confidence for the purposes of the legislation. For example, it is not clear whether a defeat on the Government’s budget would be considered as a vote of no confidence." It went on to suggest that "One possibility would be for the Government to make it clear before such a division that they considered it to be a matter of confidence; then the Speaker would certify it as such. This would effectively allow the Government to table a constructive vote of no confidence."

But the Commons Information Office confirmed to me that this was not an option legally available to the government.

I asked earlier whether, rather than resigning, Cameron would abandon centuries of parliamentary convention. It turns out he already has.

The Brexit Beartraps, #2: Could dropping out of the open skies agreement cancel your holiday?

So what is it this time, eh? Brexit is going to wipe out every banana planet on the entire planet? Brexit will get the Last Night of the Proms cancelled? Brexit will bring about World War Three?

To be honest, I think we’re pretty well covered already on that last score, but no, this week it’s nothing so terrifying. It’s just that Brexit might get your holiday cancelled.

What are you blithering about now?

Well, only if you want to holiday in Europe, I suppose. If you’re going to Blackpool you’ll be fine. Or Pakistan, according to some people...

You’re making this up.

I’m honestly not, though we can’t entirely rule out the possibility somebody is. Last month Michael O’Leary, the Ryanair boss who attracts headlines the way certain other things attract flies, warned that, “There is a real prospect... that there are going to be no flights between the UK and Europe for a period of weeks, months beyond March 2019... We will be cancelling people’s holidays for summer of 2019.”

He’s just trying to block Brexit, the bloody saboteur.

Well, yes, he’s been quite explicit about that, and says we should just ignore the referendum result. Honestly, he’s so Remainiac he makes me look like Dan Hannan.

But he’s not wrong that there are issues: please fasten your seatbelt, and brace yourself for some turbulence.

Not so long ago, aviation was a very national sort of a business: many of the big airports were owned by nation states, and the airline industry was dominated by the state-backed national flag carriers (British Airways, Air France and so on). Since governments set airline regulations too, that meant those airlines were given all sorts of competitive advantages in their own country, and pretty much everyone faced barriers to entry in others.

The EU changed all that. Since 1994, the European Single Aviation Market (ESAM) has allowed free movement of people and cargo; established common rules over safety, security, the environment and so on; and ensured fair competition between European airlines. It also means that an AOC – an Air Operator Certificate, the bit of paper an airline needs to fly – from any European country would be enough to operate in all of them.

Do we really need all these acronyms?

No, alas, we need more of them. There’s also ECAA, the European Common Aviation Area – that’s the area ESAM covers; basically, ESAM is the aviation bit of the single market, and ECAA the aviation bit of the European Economic Area, or EEA. Then there’s ESAA, the European Aviation Safety Agency, which regulates, well, you can probably guess what it regulates to be honest.

All this may sound a bit dry-

It is.

-it is a bit dry, yes. But it’s also the thing that made it much easier to travel around Europe. It made the European aviation industry much more competitive, which is where the whole cheap flights thing came from.

In a speech last December, Andrew Haines, the boss of Britain’s Civil Aviation Authority said that, since 2000, the number of destinations served from UK airports has doubled; since 1993, fares have dropped by a third. Which is brilliant.

Brexit, though, means we’re probably going to have to pull out of these arrangements.

Stop talking Britain down.

Don’t tell me, tell Brexit secretary David Davis. To monitor and enforce all these international agreements, you need an international court system. That’s the European Court of Justice, which ministers have repeatedly made clear that we’re leaving.

So: last March, when Davis was asked by a select committee whether the open skies system would persist, he replied: “One would presume that would not apply to us” – although he promised he’d fight for a successor, which is very reassuring.

We can always holiday elsewhere.

Perhaps you can – O’Leary also claimed (I’m still not making this up) that a senior Brexit minister had told him that lost European airline traffic could be made up for through a bilateral agreement with Pakistan. Which seems a bit optimistic to me, but what do I know.

Intercontinental flights are still likely to be more difficult, though. Since 2007, flights between Europe and the US have operated under a separate open skies agreement, and leaving the EU means we’re we’re about to fall out of that, too.

Surely we’ll just revert to whatever rules there were before.

Apparently not. Airlines for America – a trade body for... well, you can probably guess that, too – has pointed out that, if we do, there are no historic rules to fall back on: there’s no aviation equivalent of the WTO.

The claim that flights are going to just stop is definitely a worst case scenario: in practice, we can probably negotiate a bunch of new agreements. But we’re already negotiating a lot of other things, and we’re on a deadline, so we’re tight for time.

In fact, we’re really tight for time. Airlines for America has also argued that – because so many tickets are sold a year or more in advance – airlines really need a new deal in place by March 2018, if they’re to have faith they can keep flying. So it’s asking for aviation to be prioritised in negotiations.

The only problem is, we can’t negotiate anything else until the EU decides we’ve made enough progress on the divorce bill and the rights of EU nationals. And the clock’s ticking.

This is just remoaning. Brexit will set us free.

A little bit, maybe. CAA’s Haines has also said he believes “talk of significant retrenchment is very much over-stated, and Brexit offers potential opportunities in other areas”. Falling out of Europe means falling out of European ownership rules, so itcould bring foreign capital into the UK aviation industry (assuming anyone still wants to invest, of course). It would also mean more flexibility on “slot rules”, by which airports have to hand out landing times, and which are I gather a source of some contention at the moment.

But Haines also pointed out that the UK has been one of the most influential contributors to European aviation regulations: leaving the European system will mean we lose that influence. And let’s not forget that it was European law that gave passengers the right to redress when things go wrong: if you’ve ever had a refund after long delays, you’ve got the EU to thank.

So: the planes may not stop flying. But the UK will have less influence over the future of aviation; passengers might have fewer consumer rights; and while it’s not clear that Brexit will mean vastly fewer flights, it’s hard to see how it will mean more, so between that and the slide in sterling, prices are likely to rise, too.

It’s not that Brexit is inevitably going to mean disaster. It’s just that it’ll take a lot of effort for very little obvious reward. Which is becoming something of a theme.

Still, we’ll be free of those bureaucrats at the ECJ, won’t be?

This’ll be a great comfort when we’re all holidaying in Grimsby.

Jonn Elledge edits the New Statesman's sister site CityMetric, and writes for the NS about subjects including politics, history and Brexit. You can find him on Twitter or Facebook.